1. Field of the Invention
The present invention relates generally to a barrel finishing machine that includes a cylindrical stationary barrel having an outer bottom plate at the bottom end thereof, and a rotating barrel rotatably mounted inside the stationary barrel on the lower portion of the stationary barrel in a spaced relationship to the stationary barrel and containing abrasive media including any required water and compound, if required, and workpieces being surface-finished and the like by the abrasive media, whereby the workpieces may be surface-finished by rotating the rotating barrel. More particularly, the present invention relates to a seal protecting method and apparatus for use with a spiral-flow barrel finishing machine that prevents any part of the abrasive media in solid particle and/or liquid form resulting from the surface finishing from entering the bearing for the rotary shaft and its seal, thereby protecting the bearing or its seal from any possible damage that may be caused by the abrasive media.
2. Description of the Prior Art
It is known in the art that a seal cover is provided on a boss in the bottom plate of the rotating barrel to prevent any possible damage to the seal element or bearing element in the spiral-flow barrel finishing machine (for example, Japanese Utility Model application No. Heisei 6 (1994)-42058 as now published). It is also known in the art that a stirring section is provided behind a dishlike bottom plate on the rotating barrel (for example, Japanese Utility Model application No.Heisei 6 (1994)-31944 as now published).
It is recognized that the inventions disclosed in the applications mentioned above may be effective, respectively, in preventing damage to the seal element and the bearing element and the like, but if the abrasive media in its liquid form contains large quantities of solid particles or grains that may be produced when the particular surface finishing operation such as a rough finishing operation, occurs, those grains will tend to build up in those areas which are located on the outer bottom plate of the cylindrical stationary barrel, such as the areas closer to the rotary shaft, where the liquid abrasive media is flowing relatively slowly. Those inventions therefore could not adequately prevent any possible damage to the seal element and the like.